mirror of
https://github.com/mruby/mruby
synced 2026-06-08 16:11:16 +00:00
KOBAYASHI Shuji
66211394e1
### Example:
```ruby
# example.rb
e = [1]
def e.rewind; p :r end
c = e.chain(e)
c.each{break c}.rewind
```
#### Before this patch:
```terminal
$ bin/mruby example.rb
:r
:r
```
#### After this patch (same as Ruby):
```terminal
$ bin/mruby example.rb
:r
```
63 lines
977 B
Ruby
63 lines
977 B
Ruby
##
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# chain.rb Enumerator::Chain class
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# See Copyright Notice in mruby.h
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module Enumerable
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def chain(*args)
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Enumerator::Chain.new(self, *args)
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end
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end
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class Enumerator
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def +(other)
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Chain.new(self, other)
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end
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class Chain
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include Enumerable
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def initialize(*args)
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@enums = args.freeze
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@pos = -1
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end
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def each(&block)
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return to_enum unless block
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i = 0
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while i < @enums.size
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@pos = i
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@enums[i].each(&block)
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i += 1
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end
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self
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end
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def size
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@enums.reduce(0) do |a, e|
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return nil unless e.respond_to?(:size)
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a + e.size
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end
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end
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def rewind
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while 0 <= @pos && @pos < @enums.size
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e = @enums[@pos]
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e.rewind if e.respond_to?(:rewind)
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@pos -= 1
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end
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self
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end
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def +(other)
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self.class.new(self, other)
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end
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def inspect
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"#<#{self.class}: #{@enums.inspect}>"
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end
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end
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end
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